Real-time spectrum analyzers such as the RSA6100 and RSA3400 families available from Tektronix, Inc. of Beaverton, Oreg. trigger on, capture, and analyze RF signals in real-time. These test and measurement instruments seamlessly capture RF signals so that, unlike conventional swept spectrum analyzers and vector signal analyzers, no data is missed within a specified bandwidth.
Tektronix real-time spectrum analyzers use a technology referred to as “Digital Phosphor” or alternatively as “DPX®” to produce a display referred to as a “DPX spectrum.” A DPX spectrum is formed by transforming a continuous stream of digital data that represents an input signal into a series of frequency spectra in real-time and then accumulating the frequency spectra in a database. The database provides a precise measurement of the percentage of time during the measurement period that the input signal occupied particular locations in the amplitude or power versus frequency space, also referred to as “DPX Density®.” DPX acquisition and display technology reveals signal details such as short-duration or infrequent events that are completely missed by conventional spectrum analyzers and vector signal analyzers. For more information on DPX, see Tektronix document number 37W-19638 titled “DPX® Acquisition Technology for Spectrum Analyzers Fundamentals” available at http://www.tek.com/.